Date: Fri, 10 May 2002 13:56:45 -0700 From: Terry Lambert <tlambert2@mindspring.com> To: Ramkumar Chinchani <rc27@cse.Buffalo.EDU> Cc: freebsd-hackers@freebsd.org Subject: Re: kevent subsystem Message-ID: <3CDC340D.AC3845DE@mindspring.com> References: <Pine.SOL.4.30.0205101424240.2869-100000@pollux.cse.buffalo.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
Ramkumar Chinchani wrote: > I am asking more in terms of the posix event logging mechanism being > implemented in Linux 2.5.x kernel. > > http://evlog.sourceforge.net/ > > How does the kevent mechanism of event notification and handling compare > to this scheme? The POSIX 1003.25 draft that they are referencing: http://evlog.sourceforge.net/posix_evlog.html Is much more comparable to the BEA systems, IBM MQ-Series, or Web Methods Integration Platform, or, to point to older technology like I did in my last message, the Tuxedo Transaction Monitor. The kevent mechanism is an interleaved I/O version of the "select" or "poll" interface, with bidirectional communications being possible (e.g. definition of the selection of an accept filter, when registering for accept events, etc.). The primary benefit is that, unlike other mechansims, you can funnel all events through a single multiplexer, which means that you can handle them without stalls for different interfaces (though I have yet to see S?YSVIPC intergrated, it's possible to do). Event logging is much more of a mechanism for transaction persistance than it is a replacement for select/poll/kevent. > It appears to me that the Linux event logging merely supports logging of > events in a different way that already exists via klogd. This is a more > passive technique and requiring disk usage overheads in case of huge and > rapid audits. I think I would prefer it if you called it "POSIX 1003.25 event logging", as opposed to "Linux event logging". Standards are important, and are cross-platform. But no. It's is the basis for a reliable transactioning system. It is a fundamental building block for reliable business applications. Losing an event that encapsulates a $5M transaction is something which could break your business. > On the other hand, kevent allows more active event registering and > handling... > > What would be the pros and cons of both these techniques? They are totally different problem/solution spaces. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3CDC340D.AC3845DE>